1. Field of the Invention
This invention relates to drum-type mowers providing effective cutting and windrowing of the cut crop, such as hay. The drum mowers have one or more generally vertically disposed rotating drums with the bottom of each being equipped with a relatively large diameter disc. Cutting blades rotate with the drum and disc and may be located either above or below the discs. In multiple drum mowers, the drums cooperate in pairs rotating in opposite directions to deliver the cut grass or hay rearwardly of the mower by the action of the cooperative pair of rotating drums and discs. This is especially important when crop conditioners are used in conjunction with the mowers. More particularly, the present invention relates to the use of flat L-shaped blades the vertical portions of which are spring mounted, relative to the drum, permitting yielding of the horizontal portion in a rotary direction or in a vertical direction upon striking of an obstruction and providing automatic return to its desired position. The flat blade structure inhibits torsional twisting in the blade itself while providing yielding of the blade due to the spring mounting. The flat blade structure has reduced vertical structure thereby reducing striking of foreign objects and reducing catching or jamming with cut agricultural products.
2. Description of the Prior Art
A wide variety of drum-type mowers with radially projecting cutting blades have been known to the art as exemplified by U.S. Pat. Nos. 3,389,539; 3,391,522; 3,443,369; 3,550,360; 3,735,572 and my own prior U.S. Pat. Nos. 4,160,356 and 4,292,790. Federal Republic of Germany Patent Publication No. 2,444,610 teaches horizontally swingable blades.
My own prior U.S. Pat. No. 4,292,789 teaches L-shaped spring wire blades for use on multiple drum-type mowers wherein the vertical portion of the spring wire blade provides a torsional twist yielding when the horizontal leg strikes and obstruction. The only movement of the horizontal portion of the blade taught by my U.S. Pat. No. 4,292,789 arises from flexing action or torsional action in the vertical portion of the L-shaped spring wire blade. The U.S. Pat. No. 4,292,789 teaches that the L-shaped blades are fixedly held to the drum at the top of the blade. Federal Republic of Germany Patent Publication No. 2,422,651 teaches L-shaped blades having their vertical portions locked in place.